Method and apparatus for producing smooth-edge blanked sheet metal parts



Jan. 13, 1970 o. W. STOECKLI METHOD AND APPARATUS FOR PRODUCINGSMOOTH-EDGE BLANKED SHEET METAL PARTS 7. 1967 3 Sheets-Sheet l FiledDeo.

Jan. 13, 1970 O. W. STOECKLI METHOD AND APPARATUS FOR PRODUCINGSMOOTH-EDGE BLANKED SHEET METAL PARTS Filed Dec. 7, 1967 5 Sheets-Sheet2 'Le i x 14 ,lo 8l l 48 8 1 "lo l, e l o a4 "ig be 9a O @5 1g m O 58 sa"-25 BB' i O di l 10j nl O se @um mf@ 80 a@ I4 f A H' 2 l ma *n 4 ,i E

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METHOD AND APPARATUS FOR PRODUCING SMOOTH BLANKED SHEET METAL PARTSFiled Dec. 5 Sheets-Sheet 3 MN5/v70?, 0504,@ /14 570504/ BY @MMC/wwUnited States Patent O 3,488,987 METHOD AND APPARATUS FOR PRODUCINGSMOOTH-EDGE BLANKED SHEET METAL PARTS Oscar W. Stoeckli, 130 TheodoreFremd Ave., Rye, N.Y. 10580 Filed Dec. 7, 1967, Ser. No. 688,930 Int.Cl. B21d 31/02 U.S. Cl. 72-329 ABSTRACT OF THE DISCLOSURE A method andmeans for forming sheet metal parts by a machine which includes compounddies. As the machine operates, its stroke moves a punch and dierelatively toward one another to blank the outside contour of the sheetmetal parts. A further punch and die thereafter shaves the outer edgesof the blanked part to provide a smooth edge surface. The blanking andshaving are performed during a single stroke of the machine, and, if itis desired to have internal holes in the part, a piercing operation canalso be performed during such single stroke.

This invention relates to the fabrication of parts formed from sheetmetal or the like and more particularly it relates to a method andapparatus wherein the parts are blanked to the desired configuration,and thereafter, the edges of the blanked parts are shaved to provide asmooth outer edge which is free from burrs.

There are many well known forms of blanking devices for producing sheetmetal parts and one satisfactory form of such apparatus is shown in myprior U.S. Patent No. 3,216,299, issued Nov. 9, 1965. In general, allsuch prior devices, including the one shown in my aforementioned patent,utilize punch and die arrangements for forming a particularly shapedpart out of a larger piece of metal. Basically, the sheet of metal to beblanked is interposed between a punch and a punching die and thesemembers are moved relatively to each other to thus blank out a part of aparticular configuration. The configuration is determined by theparticular shape of the punch and the punching die. In many instances,it is often desired to provide one or more apertures or perforationswithin the part being blanked out from the sheet of metal, andaccordingly, means are often provided to perform such a piercingoperation simultaneously with the blanking operation.

Naturally, it will be understood that once a part or series of partshave been punched or blanked from a large sheet of metal, the outsideedges of the individual parts often have burrs, tangs and otherimperfections. It is thus desirable to shave or otherwise smooth theseouter edge surfaces to provide a clean and even edge on the final part.Of course, it is possible to smooth the edges by a separate sanding orsmoothing operation after the blanking has been completed, but such aprocedure is more expensive since it involves a separate machiningoperation. Thus, it would naturally be desirable and beneficial toaccomplish the smoothing or shaving operation in cornbination with theblanking or punching operation.

In my aforementioned patent, there was described an arrangement, which,in its most basic sense, accomplished the punching or blanking operationduring a downstroke of the apparatus and accomplished the shavingoperation during the upstroke of the apparatus. In contrast to thearrangement of my prior patent, however, the present inventionaccomplishes both the punching and shaving operations during a singleunidirectional stroke of the apparatus.

Claims "ice The prime object of the present invention is to provide amethod and apparatus which produces blanked and shaved metal parts andwhich accomplishes both the blanking and shaving operations during asingle stroke of the apparatus, preferably, the downstroke.

Another object of the present invention is to provide an improved methodand means for accomplishing a seriatim punching and shaving operation toprovide smooth edged blanked metal parts.

Another object of the present invention is to provide a combinationpunching and shaving apparatus for producing sheet metal parts, suchapparatus being operable in a simple yet efficient manner to assure thatsuch parts are produced with smooth edges and with the minimum degree ofmovement of the apparatus itself.

Another object of the present invention is to provide a method andapparatus for punching and shaving sheet metal parts with a higherdegree of speed and eiciency than was heretofore possible.

Other objects, advantages and salient features of the present inventionwill become apparent from the following detailed description which,taken in conjunction with the annexed drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

FIGURES 1-5 are diagrammatic side elevational views, partly in section,showing the progressive operation of apparatus in accordance with thepresent invention and caapble of performing the method aspects thereof;and,

FIGURE 6 is a top plan view of the apparatus of FIG- URES 1-5.

With continued reference to the drawings, there is shown in FIGURE 1,apparatus in accordance with the principles of the present invention,and suitable for carrying out the method aspects thereof. Such apparatusis generally designated 10 and it includes a generally flat base plate12 having a pair of spaced apart upstanding guide posts or columns 14. Ahead plate 16 is mounted in spaced relationship above the base plate 12and apertures are provided within the head plate so that the guidecolumns 14 can pass therethrough. As a result, the head plate 16 can bemoved toward and away from the base plate 12, with such movement beingguided by the columns 14. In considering the stroke of the apparatus 10,if it is assumed that the base plate 12 is fixed, then movement of thehead plate 16 toward the base plate can be regarded as the downstrokeand movement of the head plate away from the base plate can beconsidered as the upstroke.

The head plate 16 carries four spaced apart laterally extending pins 18which serve as pivot pins for mounting four lock mechanisms generallydesignated 20. The details of these lock mechanisms will be describedshortly hereinafter. For the present, it is sufficient to state' thatthe locking mechanisms 20 releasably engage laterally extending pins 22which project from a pair of linkage members 24 disposed above the headplate 16.

Each linkage member 24 carries the locking pins 22, extending laterallyfrom opposite sides thereof, and additionally, each member 24 carries apair of laterally extending pivot pins 26 which serve to mount fourdepending connecting links links 28. The links 28, in turn, arepivotally mounted at 30 to a Shaving die mounting plate 32 which carriestherewithin, a shaving die 34, which is thus more or less suspended bythe connecting links 28. Preferably, the shaving die 34 is removablyattached to the shaving die mounting plate 32 to enable such die to bereplaced, if desired.

A blanking die 36 is carried on the underside of the head plate 16 inspaced relation above the shaving die 34 and the strip of stockmaterial, designated S, from which 3 the parts are to be formed isinterposed in the spaced between these dies 34 and 36.

The head plate 16 also carries a pair of centrally disposed andlaterally spaced apart upstanding guide posts 38 whose purpose is toposition a movable shaving punch guide plate 40. A series of bolts 42extends between the guide plate 40 and the head plate 16 and compressionsprings 44 are disposed in surrounding relationship to the bolts 42 toassure that the plate 16 and 40 are normally urged away from each other.

As can be noted, the shaving punch guide plate 40 is provided along itsedges with a pair of raised ridges or `beads 46 which nest cooperativelyin grooves or channels 48 formed in the linkage members 24. The guideplate 40 also has a threaded central aperture 50 which receives the endof an elongated bolt 52. A top plate means 54 is provided above thelinkage members 24 so that the lower edge of the top plate means 54abuts against the upper edge of the linkage members 24. The top plate 54is maintained in position due to the fact that the elongated bolt 52extends therethrough and threads into the aperture 50 of the shavingpunch guide plate 40.

The central axis of the apparatus can be generally considered as theaxis passing along the elongated bolt 52. As such, the die openings andpunches are positioned along this central axis. More specically, thereis provided a shaving punch mounting plate 56 attached beneath a spacer58 carried on the underside of the shaving punch guide plate 40. Bolts60 connect from this mounting plate 56 into the enlarged, shoulderportion of a shaving punch 62. A blanking punch 64 is mounted upon thebase plate 12 in coaxial alignment with the shaving punch 62. The crosssectional configuration of the punches 62 and 64 is substantially thesame, and, quite naturally, openings must be provided within the shavingand blanking dies 34 and 36 respectively to accommodate these punches.Thus a die opening 66 is provided in the shaving die 34 to act as arelief for the piece after it passes through shaving. A similar dieopening 68, provided in the blanking die 36, is the die clearancenecessary for blanking.

The shaving punch 62 carries a spring loaded pin 70 which functions tostrip the blanked piece from the punch to prevent the piece fromsticking to the punch after the machining operations have beencompleted. If it is desired to form the part with one or more holes orapertures therein, a piercing means must be provided to accomplish thepiercing operation concurrently with the kblanking operation. To thisend, a piercing punch 72 can be provided. This piercing punch is mountedwithin the shaving punch mounting plate 56 and depends through a bore inthe shaving punch 62. An aligned bore 74 must be provided in theblanking punch 64 for receiving the end of the piercing punch 72 duringthe piercing operation, as will be described in greater detailhereinafter. The bore 74 can extend right through the base plate 12 sothat the slugs or pierced pieces from the strip S can drop into asuitable scrap pile.

It will be noted that the base plate 12 includes a series of recesses76, each of which carries a compression spring 78 aligned generallybeneath the connecting links 28. Also, it will be noted that a series ofupstanding release pins 80 are carried by the base plate 12, suchrelease pins being engageable with the lock mechanisms for the purposeof operating the same in a manner to be described in greater detailhereinafter.

With the foregoing description in mind, it is believed that thekoperation of the apparatus 10 now can be described. In this connection,attention is directed generally to FIGURES 1 through 5. Let it -beassumed that the apparatus is initially in the condition shown in FIGURE1 and the strip stock S is inserted into the position shown in thisfigure. As the apparatus starts to operate and the movable assemblystarts to descend toward the base plate 12, which is normally fixed inposition, the apparatus starts to move from the position of FIGURE 1 tothat shown in FIGURE 2. Thus it will be noted from FIGURE .4 2 that theshaving die mounting pate 32 contacts the upstanding compression springs78 extending above the base plate and starts to compress the same.Naturally, at the same time, the shaving die 34 is moved downwardly pastthe blanking punch 64 so that the upper surface of the blanking punch 64passes through the die opening 66 in the shaving die 34 and contacts theunderside of the strip stock S.

By the time that the apparatus 10 fully reaches the position shown inFIGURE 2, the blanking punch 64 will have moved to at least theunderside of the blanking die 36. Such movement will have forced thestrip stock S up into the opening 68 in the blanking die thereby servingto blank the particular piece or part out of the remainder of the stripstock. Also, the piercing punch 72 will pass through the strip stock Sand into the opening 74 in the blanking punch thereby forming a suitablehole or aperture in the part being blanked. The shaving punch 62 iselevated, by an amount equal to the thickness of the strip stock S andsuch elevation necessarily reduces the space or gap 110 between the topof the shaving punch 62 and the bottom of the shaving punch mountingplate 56. Thus, by the time that the apparatus reaches the positionshown in FIGURE 2, the blanking and piercing operations will have beencompleted and the piercing punch 72 itself is projected through theblanked out piece to thus generally maintain the piece in position andprevent it from shifting.

As the downstroke of the apparatus continues from the position shown inFIGURE 2 toward the position shown in FIGURE 3, the release pins startto release or unlock the lock mechanisms 20. At this point, it might bewell to consider the specic details of the lock members 20. As can beseen, each lock mechanism 20 includes a body member 82 pivotally mountedupon the pins 18. The body member 82 includes a groove or channel 84 forreceiving the locking pins 22 on the linkage members 24. A release arm86 is pivotally mounted by a pivot pin 88 at the bottom of the bodymember 82 and the pivot pin 88 is generally aligned beneath the pivotpin 18 which mounts the entire lock mechanism 20. The body member 82carries a spring biased plunger 90 which is urged against one end of therelease arm 86 to normally maintain the same in the position shown inFIGURES 1 and 2. At the opposite end of the release arm 86, anupstanding link plate 92 is provided. The link plate 92 is pivotallymounted at its lower end to the release arm 86, and at its upper end,the link plate 92 carries a roller 94 which engages between the back ofthe body member 82 `and a lock back-up plate 96 attached by bolts 98 tothe edges of the head plate 16. The back of the body member 82 is cutaway at its lower portion, as indicated by the reference numeral 100,and an adjustable stop member 102 is carried by the release arm 86 forpurposes of limiting the pivotal motion thereof to a predeterminedamount.

As can be noted from FIGURE 3, continuing downstroke of the mechanismcauses the inner portion of the release arms 86, on the lock mechanisms20, to come into engagement with the release pins 80 mounted on the baseplate 12. Thereafter, as the downstroke continues, the release pins 80cause the release arms 86 to pivot against the action of the springbiased plungers 90 and as a result. the link plate 92 and the roller 94are moved downwardly until the roller 94 enters the undercut portion 100of the lock body. At this time, the lock body 82 is released so that thesame can pivot about its pivot pin 18.

Simultaneously, it will be noted that the space or gap between the topof the shaving punch 62 and the bottom of the shaving punch mountingplate 56 gradually diminishes from the size shown in FIGURE 2, whenblanking has been completed, to zero as shown in FIG- URE 4 when thelocks are completely open. This gap 110 is provided for the purpose ofassuring a time lapse between completion of the blanking operation andcommencement of the shaving operation.

As will be understood by a comparison of the apparatus in FIGURE 3 withthat of FIGURE 4, as soon as the lock bodies 82 have been pivoted farenough to release the lock engaging pins 22 from the lock grooves orchannels 84, the full force of the compression springs 78 is directedthrough the connecting links 28 to the linkage members 24. This causesthe linkage members 24 to move from the position shown in FIGURE 3 tothat shown in FIGURE 4. Additionally, the shaving die '34 and blankingdie 36 are forced toward one another `to thereby clamp the blanked outstrip stock S therebetween to prevent it from moving and inadvertentlyfouling the apparatus.

If attention will now be directed to FIGURE 4, the shaving operationperformed by the present invention can now be described. It will benoted from AFIGURE 4 that as the downstroke of the apparatus continues,the top plate 54 presses against the inner ends of the disengagedlinkage members 24. It will be noted that the blanked out piece P is nowsolidly held between the Vshaving punch 62 and the blanking punch 64 andthat there is no further gap between the shaving die 34 and the blankingdie 36. Instead, it will be seen that between the base plate 12 and theshaving punch guide plate 40, there is asolid column of material formedby the spacer 58, the shaving punch mounting plate 56, the shaving punch62, the blanked out piece of material P and the blanking punch' 64. Thissolid column forms a support which applies maximum pressure to theblanked out piece during the shaving operation and prevents anyflexingor twisting thereof, The side ridges or beads 46 on the shaving punchguide plate 40 act as pivot hinges for the linkage members 24.

Thus, as the downstroke of the apparatus continues and enters its finalstage, the continued force which the top plate 54 applies to the innerend of the linkage members 24, causes the linkage members 24 to pivotand thereby raise or lift the connecting links 28 in a directionopposite to the downstroke. As the connecting links28 thus moveupwardly, the shaving die mounting plate 32 and the shaving die 34supported thereby are also moved upwardly. This draws the shaving dieopening 66 across the outer surface of the blanked out piece P' and suchmovement continues until, as shown in FIGURE 4, the combined downstrokeof the apparatus and upward stroke of the shaving die 34 causes theouter edge of the blanked out piece P to be completely shaved and causesthe remainder of the metal strip or stock S to be positively retainedbetween the shaving die 34 and the blanking die 36.

Once the entire downstroke has been completed, the piece P will not onlybe blanked out from the strip stock S, but the outer edges of the piecewill be shaved and any internal openings will have been pierced. As thereturn or upstroke of the apparatus begins, the springs 44 cause theshaving punch guide plate 40 to be pushed upwardly, thereby pivoting thelinkage members 24 outwardly and hence lowering the connecting links 28,the shaving die mounting plate 32 and the shaving die 34 carriedthereby. Likewise, the springs 106 react against the bolts 60 whichcarry the shaving punch 62 and this causes the gap 110 to open again.Thus, the piercing punch 72 is drawn into the shaving punch 62 and thisrelative movement causes the blanked out piece P to be stripped off ofthe piercing punch or punches 72. Since the speed of reaction of thesprings 44 and 106 is somewhat faster than the return or upstroke of thepress, the springs 78 serve as a resisting force which tends to hold theupper part of the apparatus in the position of FIGURE 4.

After the entire return stroke or upstroke has been completed, thelinkage members 24 again are re-locked by having the locking pins 22engage with the grooves or channels 84 in the lock members 20. Thus, ascan be seen from FIGURE 5, when the cycle is completed, the final orfinished blanked out piece P is resting freely on the top of theblanking punch 64. This piece P, of course, has been blanked, shaved andpierced, and the same can then be removed by an air blast or by somemechanical means, or less advantageously, even removed manually. Theslug 112 from the piercing operation drops through the bore 74 in theblanking die 64 and base plate 1`2, while the remaining scrap rests uponthe top of the shaving die 34. Since this scrap is usually integrallyconnected with the remaining part of the strip stock S, the scrap itselfcan be removed from the apparatus merely by suitably advancing the stripstock until an imperforate part is disposed over the shaving die 34.Then, the foregoing operation can be repeated and a new piece will beblanked, shaved and pierced. Of course, if desired, the Operation of theapparatus, and hence the performance of the method, can be madesequential or automatic by any well known type of control device.

After reading the foregoing detailed description, it should be apparentthat the objects set forth at the outset of the specification have beensuccessfully achieved by the present invention.

What is claimed is:

1. In the method of producing formed parts from sheet stock by movingfirst and second means relatively toward one another as the strip stockis interposed therebetween, the improvement which comprises:

providing a blanking punch assembly on one of said means;

providing a blankingdie assembly on the other of said means;

moving one of said means in a given direction toward the other of saidmeans until said blanking punch assembly contacts said sheet stock andforces at least a portion thereof partially into said blanking dieassembly to thereby blank a part out of said sheet stock;

providing a shaving assembly for smoothing the edges of said blanked outpart;

moving at least a part of said shaving assembly in a direction oppositeto said given direction while Continuing to move said one of said meansin said given direction to thereby shave said blanked out part; and

moving said one of -said means in a direction opposite to said givendirection after said shaving assembly ceases moving, thereby separatingsaid means and providing a formed part having shaved edges.

2. The improvement defined in claim 1 further including the step ofpiercing said part as said part is being blanked out of said sheetstock.

3. Apparatus for producing formed parts from sheet material, comprising:

a first plate member including a blanking punch;

a second plate member including an opening aligned with said blankingpunch;

guide means between said rst and second plate members to permit one tobe moved relatively to the other While maintaining said opening inalignment with said blanking punch;

blanking die means interposed between said first and second platemembers;

shaving die means interposed between said blanking die means and saidfirst plate member;

said blanking die means and shaving die means each including a dieopening aligned with said blanking punch;

a shaving punch extended through said second plate member opening and atleast partially through said blanking die opening;

mounting means coupling said blanking die means and said shaving diemeans to said second plate member in a manner which permits relativemovement between said blanking die means and said shaving die means; and

operating means coupled with said mounting means for moving saidblanking die means and shaving die means relative to each other;

said sheet material being insertable between said blanking and shavingdie means in alignment with their respective die openings;

said apparatus being operable by moving said first and second platemembers relative to one another to cause said Iblanking punch to passthrough said shaving die opening into contact with said sheet materialto force said sheet material at least partially into said blanking dieopening, thereby blanking a part from said sheet material; saidoperating means being operable after said part has been blanked fromsaid sheet material to move said shaving die means toward said blankingdie means thereby moving said shaving punch at least partially into saidshaving die opening to smooth the edges on the blanked part while itremains retained in position between said shaving and blanking punches.

4. Apparatus as defined in claim 3 further including a piercing punchmovably mounted within said shaving punch and projectable beyond the endof said shaving punch and a bore means formed within said blanking punchin alignment with said piercing punch, whereby, as said piercing punchis projected, it passes through the part retained between said blankingand shaving punches and at least partially into said bore means, therebypiercing an aperture in said part.

5. Apparatus as defined in claim 3 wherein said operating means includesmovable linkage means and wherein said mounting means includesconnecting link means operatively connected between said linkage meansand said shaving die means.

6. Apparatus as defined in claim 5 further including a shaving punchmounting plate which has at least one portion which engages said linkagemeans and acts as a fulcrum therefor.

7. Apparatus as defined in claim 6 wherein said operating means furtherincludes an additional plate member juxtaposed to said shaving punchmounting plate and engaged with said linkage means, said additionalplate member being movable relative to said shaving punch mounting plateto pivot said linkage means about said fulcrum to thereby move saidconnecting link means and thus move said shaving die means toward saidblankng die means for smoothing the edges of said part.

8. Apparatus as defined in claim 7 further including lock means mountedon said second plate member, said lock means including an engagingportion which operatively abuts against said linkage means to preventsaid pivotal movement thereof, said lock means further including a lockrelease means which releases said engaging portion from operativeabutting against said linkage means so that said linkage means canpivot.

9. Apparatus as defined in claim 8 further including means carried bysaid first plate member which actuates said lock release means when saidfirst and second plate members havel been moved relatively to oneanother for a preselected amount.

10. Apparatus as defined in claim 3 further including compressionlspring means carried by said first plate member in alignment with saidmounting means for exerting a biasing effect on said mounting means whensaid first and second plate members have been moved relatively to oneanother for a preselected amount.

References Cited UNITED STATES PATENTS 1,192,066 7/1916 Jaffe 72-3282,312,749 3/ 1943 Bullock 72-327 2,985,128 5/1961 Henrickson 72-3283,216,299 11/1965 Stoeckli 83-160 3,236,088 2/1966 Moller 72-3283,372,569 3/1968 Bozek 72-335 3,274,818 9/1966 Henrickson 72--336CHARLES W. LANHAM, Primary Examiner E. M. CoMBs, Assistant Examiner U.S.Cl. X.R.

